Succession showing changes in communities at a place is called

Given below is a figure of an ecosystem. Answer the following questions.
$(i)$ What type of ecosystem is shown in the figure?
$(ii)$ Name any plant that is characteristic of such an ecosystem.

Which of the following is $NOT$ included in a food chain?

$A$ food chain consists of:

In a pond,we see plants which are free-floating; rooted-submerged; rooted-emergent; and rooted with floating leaves. Identify the type of plant for each of the following:

Plant Name	Type
$(1)$ Hydrilla	....................
$(2)$ Typha	....................
$(3)$ Nymphaea	....................
$(4)$ Lemna	....................
$(5)$ Vallisneria	....................

Which one of the following contains very low concentrations of dissolved inorganic nutrients for algal growth?